营养及环境条件对黄色短杆菌WL-10发酵生产L-异亮氨酸的影响

Effects of Nutritional and Environmental Conditions on the Production of L-Isoleucine by Brevibacterium flavum WL-10

研究了能积累 L 异亮氨酸的黄色短杆菌WL 10的菌体生长规律 ,并讨论了葡萄糖、玉米浆以及磷酸盐等几个主要的营养物质对其积累L 异亮氨酸的影响 ,确定了较优的发酵条件为 :葡萄糖 12 % ,(NH4) 2 SO42 % ,玉米浆 2 % ,KH2 PO40 1% ,MgSO40 0 5 % ,CaCO33% ,种龄 9h ,接种量为 6 %。在此条件下 72h摇瓶产酸可达 2 3%左右。在上述基础上 ,研究了不同温度对WL 10积累L 异亮氨酸的影响 ,提出了分阶段变温控制的操作模式 ,即 0～2 5h ,培养温度为 31℃ ,2 5h后将温度降为 2 8℃ ,采用 5L罐实验 6 0h可积累L 异亮氨酸2 5 %。

In this paper the growth curve of a L-isoleucine producer Brevibacterium flavum WL-10 was studied and the effects of various factors such as carbon and phosphorous sources etc on its production of L-isoleucine were also investigated.The optimal fermentation conditions were determined:glucose 12%,(NH 4) 2SO 4 2%,corn steep liquor 2%,KH 2PO 4 0.1%, MgSO 4 0.05%,CaCO 3 3%, seed culture time 9h and inoculum size 6%. 2.3% L-isoleucine was accumulated in 72?h by shaking flask experiment. Furthermore,the effect of temperature on its production was also investigated and a temperature-shifted controlling manner was proposed:0～25?h,culture temperature is 31℃, and it is shifted down to 28℃ after 25h.In 5L jar fermentor experiment,2.5% L-isoleucine was accumulated in 60?h by using this controlling manner.